Conventionally, a fluid transfusion line or a blood transfusion line has been utilized to supply a fluid, such as medicinal liquid or blood, to a patient. In such cases, a flow rate regulator is used to regulate the flow rate of the fluid so that it flows through the tube at the correct speed. For example, Japanese Kokai Patent Application No. Hei 6[1994] 109147, shows flow rate regulators including a roller clamp which utilizes a roller. In the case of said roller clamp, guide grooves are formed on the respective inner surfaces of a pair of side walls provided on either side of a flat bottom plate, and a support shaft is placed across said guide grooves in order to allow the roller to move in the length direction.
In addition, the height between the surface of the bottom plate and the guide grooves is altered at the part along the length direction of the bottom plate, and a planar groove and protruded rows formed along the edge parts of the flat groove are provided on the top surface of the bottom plate along the length of the bottom plate. Then, the position of the roller relative to the bottom plate changes while the tube is placed between the bottom plate and the roller in order to regulate the flow rate of the fluid that flows through the tube.
However, if the tube of the aforementioned conventional roller clamp is pulled abruptly when the patient receiving the fluid rolls over or when a person or an object comes into contact with it, the position of the roller changes, and the flow rate of the fluid that flows through the tube may change.